| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package androidx.contentpager.content; |
| |
| import static androidx.core.util.Preconditions.checkArgument; |
| |
| import android.content.ContentResolver; |
| import android.database.Cursor; |
| import android.net.Uri; |
| import android.os.Build; |
| import android.os.Bundle; |
| import android.os.CancellationSignal; |
| import android.util.Log; |
| |
| import androidx.annotation.NonNull; |
| import androidx.annotation.Nullable; |
| |
| import java.util.Arrays; |
| |
| /** |
| * Encapsulates information related to calling {@link ContentResolver#query}, |
| * including the logic determining the best query method to call. |
| */ |
| public final class Query { |
| |
| private static final boolean DEBUG = true; |
| private static final String TAG = "Query"; |
| |
| private final Uri mUri; |
| private final @Nullable String[] mProjection; |
| private final Bundle mQueryArgs; |
| |
| private final int mId; |
| private final int mOffset; |
| private final int mLimit; |
| |
| private final CancellationSignal mCancellationSignal; |
| private final ContentPager.ContentCallback mCallback; |
| |
| Query( |
| @NonNull Uri uri, |
| @Nullable String[] projection, |
| @NonNull Bundle args, |
| @Nullable CancellationSignal cancellationSignal, |
| @NonNull ContentPager.ContentCallback callback) { |
| |
| checkArgument(uri != null); |
| checkArgument(args != null); |
| checkArgument(callback != null); |
| |
| this.mUri = uri; |
| this.mProjection = projection; |
| this.mQueryArgs = args; |
| this.mCancellationSignal = cancellationSignal; |
| this.mCallback = callback; |
| |
| this.mOffset = args.getInt(ContentPager.QUERY_ARG_OFFSET, -1); |
| this.mLimit = args.getInt(ContentPager.QUERY_ARG_LIMIT, -1); |
| |
| // NOTE: We omit mProjection and other details from ID. If a client wishes |
| // to request a page with a different mProjection or sorting, they should |
| // wait for first request to finish. Same goes for mCallback. |
| this.mId = uri.hashCode() << 16 | (mOffset | (mLimit << 8)); |
| |
| checkArgument(mOffset >= 0); // mOffset must be set, mLimit is optional. |
| } |
| |
| /** |
| * @return the id for this query. Derived from Uri as well as paging arguments. |
| */ |
| public int getId() { |
| return mId; |
| } |
| |
| /** |
| * @return the Uri. |
| */ |
| public @NonNull Uri getUri() { |
| return mUri; |
| } |
| |
| /** |
| * @return the offset. |
| */ |
| public int getOffset() { |
| return mOffset; |
| } |
| |
| /** |
| * @return the limit. |
| */ |
| public int getLimit() { |
| return mLimit; |
| } |
| |
| @NonNull ContentPager.ContentCallback getCallback() { |
| return mCallback; |
| } |
| |
| @Nullable Cursor run(@NonNull ContentResolver resolver) { |
| if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) { |
| return resolver.query( |
| mUri, |
| mProjection, |
| mQueryArgs, |
| mCancellationSignal); |
| } |
| |
| if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) { |
| if (DEBUG) Log.d(TAG, "Falling back to pre-O query method."); |
| return resolver.query( |
| mUri, |
| mProjection, |
| null, |
| null, |
| null, |
| mCancellationSignal); |
| } |
| |
| if (DEBUG) Log.d(TAG, "Falling back to pre-jellybean query method."); |
| return resolver.query( |
| mUri, |
| mProjection, |
| null, |
| null, |
| null); |
| } |
| |
| void cancel() { |
| if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) { |
| if (mCancellationSignal != null && !mCancellationSignal.isCanceled()) { |
| if (DEBUG) { |
| Log.d(TAG, "Attemping to cancel query provider processings: " + this); |
| } |
| mCancellationSignal.cancel(); |
| } |
| } |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (obj == null) { |
| return false; |
| } |
| |
| if (this == obj) { |
| return true; |
| } |
| |
| if (!(obj instanceof Query)) { |
| return false; |
| } |
| |
| Query other = (Query) obj; |
| |
| return mId == other.mId |
| && mUri.equals(other.mUri) |
| && mOffset == other.mOffset |
| && mLimit == other.mLimit; |
| } |
| |
| @Override |
| public int hashCode() { |
| return getId(); |
| } |
| |
| @Override |
| public String toString() { |
| return "Query{" |
| + "id:" + mId |
| + " uri:" + mUri |
| + " projection:" + Arrays.toString(mProjection) |
| + " offset:" + mOffset |
| + " limit:" + mLimit |
| + " cancellationSignal:" + mCancellationSignal |
| + " callback:" + mCallback |
| + "}"; |
| } |
| } |